Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van chat » cao chat
lang van » dang van, tang van, hoang van
hanh vu » hanh vi, hanh va, hanh tu
va hanh » van hanh, va thanh, va danh
ve chat » va chat
van hoi » van hoa, van hoc, van hoe
ky lang » ky nang, ky dang, ky tang
su sach » so sach, vu sach
xuc va » duc va, tuc va, luc va
vu va » vu van, tu va, su va
thiet » thieu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (su sach)) ky lang van hoi. hieu ((ve chat) or (van chat)) xuc va hanh vu va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (su sach)) ky lang van hoi. hieu ((ve chat) OR (van chat)) xuc va hanh vu va thiet.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (su sach)) ky lang van hoi. hieu ((ve chat) or (van chat)) xuc va hanh vu va thiet*.